Activity-dependent multi-mode physiological sensor

ABSTRACT

Disclosed are systems and methods for using one or more light sources and associated photodetectors to determine different physiological parameters of a subject based on the subject&#39;s activity state. A processor may, for example, be configured to determine, based at least in part on data received from an accelerometer at a first time, that a first physiological parameter of the subject is to be determined, to cause the light source(s) to operate in a first manner and process signals from the photodetector(s) to determine the first physiological parameter, to determine, based at least in part on data received from the accelerometer at a second time, that a second physiological parameter of the subject is to be determined, and to cause the light source(s) to operate in a second manner and process signals from the photodetector(s) to determine the second physiological parameter.

RELATED APPLICATIONS

This is a continuation of U.S. application Ser. No. 15/610,974,published as U.S. Pat. App. Pub. No. 2017/0265769, and now pending,entitled “A HEALTH-MONITOR PATCH,” filed Jun. 1, 2017, which is adivisional of U.S. application Ser. No. 15/266,767, published as U.S.Pat. App. Pub. No. 2017/0000372, and now U.S. Pat. No. 9,700,223,entitled “METHOD FOR FORMING A COMPONENT OF A WEARABLE MONITOR,” filedSep. 15, 2016, which is a continuation of U.S. application Ser. No.14/757,584, published as U.S. Pat. App. Pub. No. 2016/0242654, and nowU.S. Pat. No. 9,700,222, entitled “A HEALTH-MONITOR PATCH,” filed onDec. 23, 2015, which is a continuation-in-part of U.S. application Ser.No. 14/491,441, published as U.S. Pat. App. Pub. No. 2015/0119728, andnow pending, entitled “HEALTH MONITOR,” filed on Sep. 19, 2014, which isa continuation-in-part of U.S. application Ser. No. 13/840,098,published as U.S. Pat. App. Pub. No. 2013/0217979, and now U.S. Pat. No.9,734,304, entitled “VERSATILE SENSORS WITH DATA FUSION FUNCTIONALITY,”filed on Mar. 15, 2013, which is a continuation-in-part of U.S.application Ser. No. 13/690,313, published as U.S. Pat. App. Pub. No.2013/0158686, and now abandoned, entitled “INTELLIGENT ACTIVITYMONITORING,” filed on Nov. 30, 2012, which claims the benefit under 35U.S.C. § 119(e) to U.S. Provisional Application Ser. No. 61/566,528,entitled “INTELLIGENT ACTIVITY MONITORING,” filed on Dec. 2, 2011. Theentire contents of each of the foregoing documents is incorporatedherein by reference.

FIELD

The technology relates to wearable devices that are configured tomonitor physiological parameters (heart rate, heart rate variability,respiratory rate, etc.) of a subject and/or physical activity performedby the subject.

BACKGROUND

There currently exist small sensing devices that can be worn by a userto monitor physical activity performed by the user. As an example, theFitLinxx® ActiPed+ (available from FitLinxx, Shelton, Conn., USA) is asmall device that can be clipped to a shoe and used to monitor walkingand running activities by the user. When a user walks or runs, anon-board accelerometer outputs data that is stored on the device forsubsequent transmission to a computer system. The computer system cananalyze the data to determine activity type, and calculate variousactivity parameters (e.g., duration of activity, total steps, distancetraveled, and calories burned). Results of the data analysis may bepresented on the computer's display, so that a user may review detailsof his or her activity. The results may be stored, so that the user canmaintain a record of exercise regimens and track progress towardexercise goals, or so that the data may be used by medical personnel totrack recovery from an illness or injury. Other modern activity monitorsperform similar functions with varying degrees of accuracy.

Most activity monitors are configured to be attached to a subject'sclothing or strapped to a subject's limb. For example, some activitymonitors may clip on clothing, or be configured to clip on or lace in ashoe. Activity monitors that attach to clothing are generally notadapted to sense a physiological parameter of the subject. Some activitymonitors that may be worn on the wrist or ankle of a subject may beadapted to sense heart rate, but these monitors generally cannot measuredetails of cardiac waveform to obtain information such as heart-ratevariability (HRV) or cardiac abnormalities such as arrhythmias.

SUMMARY OF EXAMPLE EMBODIMENTS

An adhesive, health-monitor patch that can be adhered to the skin of asubject in the vicinity of the heart is described. In some embodiments,the health-monitor patch comprises a flexible and waterproof strip, andis designed to be worn for extended periods of time. Two monitoringelectrodes on the strip may contact the skin of the subject and be usedto collect cardiac waveform data. At least a third electrode may beincluded to suppress electrical noise and improve the quality of datacollected by the health-monitor patch. The cardiac waveform data may beanalyzed to determine various physiological parameters of a subject,such as heart rate, heart-rate variability, caloric burn, resting heartrate, recovery from a workout, respiratory rate, etc. The health-monitorpatch may further include an accelerometer from which acceleration datamay be analyzed to determine parameters associated with motion of thesubject (e.g., body orientation of the subject, type of activityperformed by the subject, intensity of activity performed by thesubject, etc.).

Some embodiments of a health-monitor patch may comprise a flexible stripassembly, which may house electrical components of the health-monitorpatch, and a replaceable electrode strip that adheres to the flexiblestrip assembly. The replaceable electrode strip may provide replaceableadhesion and electrical connections between the subject and the flexiblestrip assembly. Other embodiments of the health-monitor patch may besingle-use, disposable strips that include electronics and adhesivelayers for attaching to a subject's skin. A disposable health-monitorpatch may be a low-cost device suitable for single-use applications,such as for out-patient health monitoring.

A health-monitor patch may include an accelerometer, processor, andmachine-readable instructions that adapt the health-monitor patch toperform a variety of different functions and data analyses as described,for example, in U.S. Patent Application Pub. No. 2015-0119728 and inU.S. Patent Application Pub. No. 2013-0217979, the disclosures of whichwere incorporated by reference above in their entirety.

According to some embodiments, a health-monitor patch may comprise acardiac sensor comprising two monitor electrodes that are configured toreceive two signals from two locations on the skin of the subject. Ahealth-monitor patch may further include a noise electrode configured toreceive a signal from the skin of the subject at a location separatefrom the two locations of the two monitor electrodes. A health-monitorpatch may further include an electronic assembly comprising a processorconfigured to process signals from the two monitor electrodes.

Some embodiments relate to methods for operating a health-monitor patch.Some methods of operation may include acts of receiving two electricalsignals at two monitor electrodes of the health-monitor patch, whereinthe two monitor electrodes contact the skin of a subject and areseparated by a distance, conducting electrical signals from the twomonitor electrodes over two conductive paths to two signal inputs of anelectronic circuit mounted within the health-monitor patch, receiving anelectrical signal from a noise electrode that contacts the skin of thesubject and is located between the two monitor electrodes, andconducting the electrical signal from the noise electrode to aconductive shield, such as an ESD shield, that extends at least part wayover the two conductive paths. The conductive shield may also extendover the electronic circuit.

The foregoing and other aspects, embodiments, and features of thepresent teachings can be more fully understood from the followingdescription in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The skilled artisan will understand that the figures, described herein,are for illustration purposes only. It is to be understood that in someinstances various aspects of the invention may be shown exaggerated orenlarged to facilitate an understanding of the invention. In thedrawings, like reference characters generally refer to like features,functionally similar and/or structurally similar elements throughout thevarious figures. The drawings are not necessarily to scale, emphasisinstead being placed upon illustrating the principles of the teachings.The drawings are not intended to limit the scope of the presentteachings in any way.

FIG. 1A depicts a plan view of a health-monitor patch, according to someembodiments;

FIG. 1B depicts an elevation view of a health-monitor patch, accordingto some embodiments;

FIG. 1C depicts an underside view of a health-monitor patch, accordingto some embodiments;

FIG. 2A depicts a plan view of a disposable health-monitor patch,according to some embodiments;

FIG. 2B depicts an elevation view of a disposable health-monitor patch,according to some embodiments;

FIG. 2C depicts an underside view of a disposable health-monitor patch,according to some embodiments;

FIG. 3 illustrates electronic components that may be included in ahealth-monitor patch, according to some embodiments;

FIG. 4 depicts an exploded view of a disposable health-monitor patch,according to some embodiments;

FIG. 5 illustrates a noise suppression configuration and conductiveadhesive in a circuit of a health-monitor patch, according to someembodiments;

FIG. 6 illustrates infused conductors in a flexible strip assembly,according to some embodiments;

FIG. 7A depicts an exploded view of components for a replaceableelectrode strip, according to some embodiments;

FIG. 7B depicts a cross section of a replaceable electrode strip,according to some embodiments;

FIG. 8 illustrates a cardiac waveform; and

FIG. 9 illustrates a cardiac waveform obtained with a health-monitorpatch.

The features and advantages of the present invention will become moreapparent from the detailed description set forth below when taken inconjunction with the drawings.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

An example embodiment of a health-monitor patch 100 is depicted in FIG.1A. According to some embodiments, a health-monitor patch may be formedfrom flexible materials and configured to adhere to the skin of aperson. A health-monitor patch may include at least one accelerometerfor sensing motion and/or activities of a subject, and/or may includeelectrodes, one or more lasers, one or more light-emitting diodes, oneor more photodiodes, one or more temperature sensors and/or othersensors for sensing one or more physiological parameters of a subject.The inventors have recognized and appreciated that a flexible patch-typedevice that having electrodes and/or other sensors that can directlycontact a subject's skin can provide more accurate information about asubject's biophysical parameters (such as cardiac waveform, bodytemperature, respiratory rate, blood oxygenation level, blood glucoselevel, etc.), which conventional pedometers may not be able to provide.To obtain a reliable cardiac waveform signal, such a patch device ispreferably located in the vicinity of a subject's heart and includes twoor more electrodes spaced a distance apart. Accordingly, ahealth-monitor patch is preferably flexible so that it's sensingelectrodes can remain in contact with the skin of the subject as thesubject moves.

The inventors have also recognized and appreciated that a health-monitorpatch attached to a subject's torso can provide more reliableinformation about a subject's position (lying, sitting, standing) than aconventional activity monitor that straps to a subject's wrist or ankle.Torso orientation can be helpful when identifying a type of activitythat a subject is performing (e.g., distinguishing rowing from cyclingor cycling from running) or identifying a resting state of a subject.Torso orientation can also be helpful when monitoring patients. Forexample, an increased heart rate accompanied by data indicating thepatient has changed from a lying position to a vertical and/or walkingorientation may be of no concern, whereas an increased heart rate whilethe patient remains in a lying position may require the attention of acaregiver.

The inventors have further conceived of structures, circuits, processes,and combinations of materials that provide a waterproof health-monitorpatch, according to some embodiments, and a low-cost disposablehealth-monitor patch, according to some embodiments. Further details ofa health-monitor patch are described below.

Referring again to FIG. 1A, a health-monitor patch 100 may include afirst end region 110 a and a second end region 110 b. A health-monitorpatch may comprise a flexible strip assembly 105 that may or may nothave an open center 120. For embodiments that include an open center,one or more flexible ribs 107 may connect the first end region 110 a andthe second end region 110 b. For embodiments that do not have an opencenter 120, a center portion of the flexible strip assembly 105 may bethin or otherwise configured to provide flexible bending and twistingbetween the first end region and the second end region. A width W of ahealth-monitor patch 100 may be between approximately 10 mm andapproximately 50 mm, according to some embodiments.

An elevation view of a health-monitor patch 100 is depicted in FIG. 1B.In some embodiments, a health-monitor patch may comprise enlarged lobesat the end regions 110 a, 110 b as shown in the drawing. Electronics ofa health-monitor patch may be housed within the lobes. An overall lengthL of a health-monitor patch 100 may be between approximately 50 mm andapproximately 150 mm. A height H of a health-monitor patch may bebetween approximately 3 mm and approximately 10 mm. The flexible stripassembly may comprise a flexible polymer such as, but not limited to,silicone.

According to some embodiments, a replaceable electrode strip 150 may beadhered, temporarily, to a lower surface of a health-monitor patch 100,as depicted in FIG. 1B. The replaceable electrode strip may provideadhesion, electrical connections, and a waterproof seal between theflexible strip assembly and the skin of a subject. The replaceableelectrode strip may be peeled off of the lower surface of the flexiblestrip assembly 105 and replaced with a new replaceable electrode strip150. For example, a user may adhere a health-monitor patch 100 to theirskin for a period of time (e.g., one or several days, a week, or more),and then remove the health-monitor patch, replace the replaceableelectrode strip 150, and then re-adhere the health-monitor patch totheir skin for continued monitoring of activity and physiologicalparameters.

A bottom-side or skin-side view of a health-monitor patch having areplaceable electrode strip 150 is illustrated in FIG. 1C, according tosome embodiments. The replaceable electrode strip may include anadhesion surface 152 configured to adhere to a subject's skin. Thereplaceable electrode strip may comprise two or more electrodes 160 a,160 b that provide electrical contact to the subject's skin, andelectrically connect with electronic circuitry inside the flexible stripassembly 105. In some embodiments, a first monitor electrode 160 a islocated at a first end of the replaceable electrode strip 150, and asecond monitor electrode 160 b is located at a second end of thereplaceable electrode strip. A distance D between the first monitorelectrode and second monitor electrode may be between approximately 50mm and approximately 90 mm. The first monitor electrode 160 a and secondmonitor electrode 160 b may comprise hydrogel electrodes in someembodiments, or may comprise other flexible electrodes for contacting asubject's skin. A width of the replaceable electrode strip 150 may bebetween approximately 10 mm and approximately 50 mm, according to someembodiments.

In some cases, there may be one or more noise electrodes 170 locatedseparately from the first monitor electrode 160 a and the second monitorelectrode 160 b. As shown, in some embodiments, the noise electrode(s)170 may be located between the monitor electrodes 160 a, 160 b. A noiseelectrode may also comprise a hydrogel electrode or other flexibleelectrode. For some implementations, a noise electrode 170 may belocated approximately half-way between the first monitor electrode andthe second monitor electrode. In other embodiments, one or more noiseelectrodes may be placed closer to one or the other of the first monitorelectrode and second monitor electrode or at other locations on thestrip 150. A noise electrode may provide an electrical contact to theskin of a subject and further connect electrically to noise cancellationcircuitry within the flexible strip assembly 105.

A second embodiment of a health-monitor patch is depicted in FIG. 2A. Asshown, in some embodiments, a disposable health-monitor patch 200 maycomprise a flexible strip assembly 205 that includes a first end region210 a and a second and region 210 b. The length L and width W of adisposable health-monitor patch 200 may be of approximately the samecorresponding dimensions for a health-monitor patch 100 described abovein connection with FIG. 1A. Referring to FIG. 2B, a disposablehealth-monitor patch 200 may have a lower profile, and a height that isbetween approximately 2 mm and approximately 8 mm. A flexible stripassembly 205 may be more uniform in height along its length, and formedfrom a plurality of flexible layers of materials. In some embodiments,it may include bulged end regions 210 a, 210 b that accommodate thedevice's electronics (e.g., a PCB assembly and battery).

A disposable health-monitor patch 200 may not have a replaceableelectrode strip 150, but may include an adhesion surface 252. Adisposable health-monitor patch 200 may have a release liner (shown inFIG. 7A) located over the adhesion surface 252 that may be removed justprior to adhesion of the disposable health-monitor patch to the skin ofa subject. A disposable health-monitor patch may operate betweenapproximately one day and approximately 14 days on a subject, and thenbe removed and disposed.

A plan-view illustration of an adhesion surface 252 of a disposablehealth-monitor patch 200 is depicted in FIG. 2C, according to someembodiments. The adhesion surface 252 may accommodate a first monitorelectrode 260 a and a second monitor electrode 260 b. The monitorelectrodes may be separated by a distance between approximately 50 mmand approximately 90 mm, according to some implementations. Between themonitor electrodes, or at some other location on the adhesion surface252, there may be one or more noise electrodes 270. The monitorelectrodes may provide an electrical connection to the patient's skinand to sensing and data analysis circuitry within the disposablehealth-monitor patch. The one or more noise electrodes may provideelectrical connection to the subject's skin and to noise cancellationcircuitry within the disposable health-monitor patch 200. In someembodiments, there may be one or more openings through the adhesionsurface 252 for radiation to pass through from one or morelight-emitting devices 286 (e.g., laser(s), LED(s)), and forbackscattered light to pass through to one or more photodiodes 287.

In operation, a health-monitor patch may collect physiological data(e.g., cardiac data, temperature data, blood oxygenation data, etc.)and/or motion data (e.g., accelerometer data) from one or more of itssensors. In some embodiments, some of the data may be processed orpre-processed by an on-board processor of the health-monitor patch. Insome implementations, collected data may be offloaded to a remote device(e.g., a smart phone, a laptop, a tablet, a computer, etc.) which mayprocess the collected data. Data accumulated on a health-monitor patchmay be downloaded via a wireless connection. Examples of data processingand data transfer are described in further detail in U.S. PatentApplication Pub. No. 2015-0119728, incorporated by reference above.

FIG. 3 depicts some components and an example circuit 300 that may beimplemented in a health-monitor patch, according to some embodiments. Asshown, a health-monitor patch's circuitry may, for example, comprise asource of power 305 (e.g., at least one battery or energy-scavengingchip and a wake-up and power-management circuit 350) that provide andmanage power delivery to one or more of an accelerometer 330, a digitalprocessor 310, memory 320, and a transceiver 340. The processor 310 maybe coupled to one or more of the wake-up circuit, the accelerometer,memory, and the transceiver. The power source 305 and/or processor 310may be coupled to additional components, such as one or morephysiological sensors 354.

The term “digital processor” or “processor” as used herein may refer toat least one microcontroller, microprocessor, digital signal processor(DSP), application-specific integrated circuit (ASIC),field-programmable gate array (FPGA), or data-processing logiccircuitry. “Digital processor” or “processor” may also be used to referto any combination of the foregoing digital processing devices,including more than one of a particular data processing device.

The processor may be configured to receive and process data from one ormore sensors on the health-monitor patch (e.g., from the accelerometer330 and/or one or more physiological sensors 354). The processor 310 mayfurther be configured to read and write data to memory 320, and to sendand receive data from transceiver 340. The wake-up circuit 350 may beadapted to sense when the health-monitor patch is not in use, and inresponse, reduce power consumption of the internal circuit 300,according to some embodiments. The wake-up circuit may be furtheradapted to sense when the health-monitor patch is placed in use, and inresponse, activate one or more elements of the internal circuit 300.

In some embodiments, the processor 310 may, for example, comprise alow-power, 8-bit processor configured to draw low power in sleep-modeoperation, and capable of operating at multiple millions of instructionsper second (MIPS) when activated. One example of a suitable processor isthe 8051F931 processor available from Silicon Laboratories Inc. ofAustin, Tex. Another example of a processor is the nRF51822 processoravailable from Nordic Semiconductor of Oslo, Norway, though any othersuitable processor or microprocessor may alternatively be employed inother embodiments. In some implementations, the processor 310 maysupport radio-frequency communications with other devices. A balun(e.g., BAL-NRF02D3 available from ST Microelectronics of Geneva,Switzerland) may be used to match RF signals between an antenna and theprocessor, according to some embodiments.

The processor 310 may, for example, include various types of on-boardmemory (e.g., flash memory, SRAM, and XRAM) for storing data and/ormachine-readable instructions, and may be clocked by an internaloscillator or external oscillator. In some embodiments, the processormay, for example, be clocked by an internal high-frequency oscillator(e.g., an oscillator operating at about 25 MHz or higher) when theprocessor is active and processing data, and alternatively clocked by alow-frequency oscillator (external or internal to the processor) whenthe processor is substantially inactive and in sleep mode. The clockingof the processor at low frequency may, for example, reduce powerconsumption by the processor during sleep mode. The low-frequencyclocking may be at a frequency that is less than 50% of thehigh-frequency clocking in some embodiments, less than 20% of thehigh-frequency clocking in some embodiments, less than 10% of thehigh-frequency clocking in some embodiments, less than 5% of thehigh-frequency clocking in some embodiments, less than 2% of thehigh-frequency clocking in some embodiments, less than 1% of thehigh-frequency clocking in some embodiments, and yet less than 0.1% insome embodiments.

In various embodiments, the processor 310 may be configured to receiveacceleration data from accelerometer 330 and process the received dataaccording to pre-programmed machine-readable instructions that areloaded onto and execute on the processor. The processor 310 may, forexample, be configured to receive analog and/or digital input data, andmay include on-board analog-to-digital and digital-to-analog convertersand on-board timers or clocks. According to some embodiments, theprocessor may also be configured to receive and analyze cardiac waveformdata from electrodes in contact with a user's skin. In some embodiments,the processor may be further configured to receive power through wake-upand power management circuitry 350. The processor may, in someembodiments, cooperate with or comprise a portion or all of powermanagement circuitry 350, and facilitate activating and deactivating oneor more circuit elements within the health-monitor patch.

In some embodiments, the processor 310 may be configured to operate at anumber of different clock frequencies. When operating at a low clockfrequency, the processor will typically consume less power than whenoperating at a high clock frequency. In some embodiments, the processormay, for example, be configured to be in a “sleep” mode and operating ata low clock frequency when there is no motion of health-monitor patch,and to be cycled through several operating states when motion of thehealth-monitor patch is detected. As one example, when in sleep mode,the processor may sample data at a rate less than 10 Hz and draw lessthan about 30 microamps.

In some embodiments, accelerometer 330 may, for example, comprise amulti-axis accelerometer and/or gyroscopes configured to senseacceleration along at least two substantially orthogonal spatialdirections. The accelerometer 330 may, for example, comprise athree-axis accelerometer based on micro-electro-mechanical systems(MEMS) technology. In some implementations, one or more single-axisaccelerometers may additionally or alternatively be used. In someembodiments, the accelerometer 330 may be configured to provide one ormore analog data-stream outputs (e.g., X, Y, Z data outputscorresponding to each axis of the accelerometer) that are eachrepresentative of a magnitude and direction of acceleration along arespective axis. One example of a suitable accelerometer is the Kionixmodel KXSC7 accelerometer available from Kionix Inc., Ithaca, N.Y.Another example of a suitable accelerometer is the LIS2DH accelerometeravailable from ST Microelectronics of Geneva, Switzerland. Theaccelerometer 330 may, for example, provide analog output data, that maylater be converted to digital data, or may provide digital output datarepresentative of acceleration values.

The accelerometer 330 may be characterized by several parameters. Amongthese parameters may, for example, be a sensitivity value and a samplingrate value. As examples, the accelerometer's analog sensitivity may bebetween about 100 millivolts (mV) per gravitational value (100 mV/G) andabout 200 mV/G in some embodiments, between about 200 mV/G and about 400mV/G in some embodiments, between about 400 mV/G and about 800 mV/G insome embodiments, and yet between about 800 mV/G and about 1600 mV/G insome embodiments. When configured to provide a digital output, thesampling rate of the accelerometer may, for example, be between about 10samples per second per axis (10 S/sec-A) and about 20 S/sec-A in someembodiments, between about 20 S/sec-A and about 40 S/sec-A in someembodiments, between about 40 S/sec-A and about 80 S/sec-A in someembodiments, between about 80 S/sec-A and about 160 S/sec-A in someembodiments, between about 160 S/sec-A and about 320 S/sec-A in someembodiments, and yet between about 320 S/sec-A and about 640 S/sec-A insome embodiments. It will be appreciated that in some embodiments thehigher sampling rates may improve the quality of the measuredaccelerations.

It will be appreciated that, in some embodiments, an accelerometer 330may be combined with one or more analog-to-digital converters to providedigital output data representative of acceleration values at samplingrates described above. When digital output data is provided by anaccelerometer, the accelerometer's sensitivity may be expressed in unitsof bits per gravitational constant (b/G). As examples, an accelerometerproviding digital output data may have a sensitivity of more than about2 b/G in some embodiments, more than about 4 b/G in some embodiments,more than about 6 b/G in some embodiments, more than about 8 b/G in someembodiments, more than about 10 b/G in some embodiments, more than about12 b/G in some embodiments, or even higher values in some embodiments.

According to some embodiments, a health-monitor patch may include one ormore sensors in addition to motion sensor 352 and accelerometer 330. Forexample, a health-monitor patch may include at least one physiologicalsensor 354 (e.g., cardiac sensor, temperature sensor, blood glucosesensor, blood oxygenation sensor, etc.) configured to sense at least onephysiological parameter of a subject. A physiological sensor maycomprise one or more electrodes configured to provide electricalconnection to the skin of a subject in some embodiments. Othercomponents that may be used in a physiological sensor include, but arenot limited to, pressure transducers, acoustic transducers, temperaturesensing elements (e.g., thermistors, infrared sensors), light sources(e.g., LEDs or laser diodes), and photodetectors.) One illustrativeexample of a physiological sensor comprises the AD8232 ECG chipavailable from Analog Devices, Inc. of Norwood, Mass. Such a chip may becombined with electrodes arranged to contact the skin of a subject.

A physiological sensor 354 may include various signal-processingelectronics and associated circuitry. For example, a physiologicalsensor 354 may comprise input amplifiers and noise filters that processreceived signals from monitoring electrodes or other detectors. Inputamplifiers may include low-noise amplifiers and differential amplifiers.A physiological sensor 354 may be disposed, at least in part, in a samepackage with a health-monitor patch in some implementations, or may beformed as a separate monitor to be attached to the subject at a separatelocation and wirelessly, or via a wired link, transmit data to thehealth-monitor patch according to a predetermined communicationprotocol. In some implementations, a portion (e.g., a signal processingportion) of a physiological sensor may be incorporated on a printedcircuit board assembly of a health-monitor patch, whereas electrodes ordetectors for the sensor may be located off the PCB assembly. In somecases, a central processor of a health-monitor patch may comprise aportion of a physiological sensor and process signals from electrodes orother detectors to determine one or more physiological parameters.Examples of physiological parameters that may be sensed by one or morephysiological sensors 354 include, but are not limited to, cardiacwaveform, heart rate, heart-rate variability, arrhythmia, skintemperature, core temperature, respiration rate, plethysmographywaveform, EKG waveform, blood oxygenation level, blood glucose level,hydration, blood pressure, etc.

In some embodiments, a health-monitor patch may include memory 320 thatis external to and accessible to the processor 310. The memory 320 maybe any one of or combination of the following types of memory: RAM,SRAM, DRAM, ROM, flash memory. The memory 320 may, for example, be usedto store and/or buffer raw data from accelerometer 330 and/orphysiological sensor 354, machine-readable instructions for processor310, program data used by the processor for processing accelerometerdata and/or physiological data, and/or activity data representative ofan activity. In some embodiments, the memory 320 may additionally oralternatively be used to store diagnostic information about the healthof the health-monitor patch, e.g., battery life, error status, etc.,and/or technical information about the device, e.g., memory size,gravitational sensitivity, weight, battery model, processor speed,version of operating software, user interface requirements, etc. In someembodiments, the memory may also be used to store information pertinentto a user, e.g., user weight, height, gender, age, training goals,specific workout plans, activity-specific data for a user that may beused to identify an activity performed by the user or process datarepresentative of an identified activity. According to some embodiments,the memory 320 may store tables of metabolic equivalents (METs),calibration values, and health guideline data that is used to determinehealth benefit levels for various activities.

In some embodiments, the memory 320 may additionally or alternatively beused to store data structures and/or code received from an externaldevice, e.g., via a wired or wireless link. The data structures and/orcode may, for example, be used to update one or more data processingapplications used by the health-monitor patch. For example, one type ofdata structure may be data representative of an activity data patternthat may be used to identify a specific type of activity not previouslyrecognized by the health-monitor patch, e.g., a new activity or anactivity that is specific to an individual user of the health-monitorpatch. As another example, a data structure may comprise a membershipfunction, described below, defined for a new activity or redefined foran identifiable activity. According to some embodiments, the datastructure may, for example, include one or more sample accelerometertraces and physiological data obtained during performance of theactivity and/or may comprise identification data (e.g., membershipfunctions) resulting from the processing of the accelerometer tracesthat may be used in an algorithm executed by the health-monitor patch toidentify the activity. Further, in some embodiments, the memory 320 maybe used to store updates and/or replacements to algorithms executed bythe health-monitor patch. The stored data structures and algorithms may,for example, be used to reprogram and/or expand the functionality of thehealth-monitor patch to identify new activities or activities notpreviously recognized by the health-monitor patch and/or improve theaccuracy or confidence of results calculated for identified activities.

In some embodiments, the memory 320 may also be used to storecalibration and/or conversion data that is used by the processor 310 tocharacterize detected activities. Calibration data may, for example, beused to improve the accuracy of detected activity parameters (e.g.,stride length, speed), and/or improve the accuracy of fitness metricscomputed from detected activities. Conversion data may, for example, beused to convert a detected activity into an amount of expended humanenergy, e.g., calories burned, metabolic equivalents, etc.

According to some embodiments, a health-monitor patch may include atransceiver 340 and/or one or more data communication ports (e.g., a USBport, an RF communication port, a Bluetooth port) for communicating databetween the health-monitor patch and one or more external devices suchas a computer, tablet, cell phone, portable communication device, dataprocessor, a sensor, another intelligent sensor, or a versatile sensor,any of which may be configured to communicate with other similar devicesin a network such as the world-wide web or a local area network. Ahealth-monitor patch may, for example, be configured to communicate viathe transceiver 340 through a wired or wireless port to any device orcombination or devices selected from the following list: a personalcomputer, laptop computer, tablet computer, PDA, a watch, an MP3 player,an iPod, a mobile phone, a medical device such as a blood glucose meter,blood pressure monitor, or InR meter, an electronic interactive gamingapparatus, intelligent training equipment, and an automobile system.Data retrieved from the memory 320 or to be stored in memory may, forexample, be communicated between the health-monitor patch and anexternal device via the transceiver 340. In some embodiments, datatransmitted from the health-monitor patch may be configured for routingto a data service device adapted to process data received from ahealth-monitor patch.

In some embodiments, power for the internal electronics of ahealth-monitor patch may be provided by at least one battery 305 andmanaged by a wake-up and power-management circuit 350. The battery maybe small, e.g, a button-cell type, and may, for example, comprise one ormore lithium-type batteries that may be rechargeable or replaceable. Asjust one example, a single lithium coin or button-cell, 3-volt batteryhaving a capacity of about 230 mAh may be used (model CR2032 availablefrom Renata SA of Itingen, Switzerland). Another embodiment of ahealth-monitor patch may include one or more model CR1616 batteries,though any suitable type of battery may alternatively be used in variousembodiments. In some embodiments, a health-monitor patch may includepower-generation or energy-harvesting hardware (e.g., a piezo-electricmaterial or electric generator configured to convert mechanical motioninto electric current, a solar cell, an RF or thermal converter). Powerthat is generated on board may be stored in a battery or charge-storagecomponent such as a super capacitor. In some implementations, generatedelectrical current may be provided to a storage component via a diodebridge. One example of a suitable energy harvesting device is amicroenergy cell MEC225 available from Infinite Power Solutions, Inc. ofLittleton, Colo. In some embodiments, power generation components may beused in combination with a rechargeable battery as a source of power fora health-monitor patch. A voltage regulator chip (e.g., TPS78001available from Texas Instruments of Dallas, Tex.) may be used tocondition power from at least one power source before delivering thepower to components of a health-monitor patch, according to someembodiments.

According to some embodiments, a battery 305 of a health-monitor patchmay be recharged wirelessly. For example, a health-monitor patch mayinclude a conductive coil that can inductively couple electromagneticenergy from an alternating magnetic field. Current from the coil may beprovided to a rectifying circuit that converts the alternating currentinto a direct current that can be used to charge a battery 305.

In some implementations, wake-up and power-management circuitry 350 mayinclude a motion sensor 352 that, in combination with the wake-up andpower-management circuitry 350, identifies when a health-monitor patchis being moved in a manner that may be representative of an activity tobe monitored. The wake-up and power-management circuitry 350 may, forexample, comprise logic and control circuitry to enable, disable, reduceand/or increase power to various circuit elements shown in FIG. 3. Logicand control circuitry for the wake-up and power-management circuitrymay, for example, comprise machine-readable instructions and utilizedhardware of the processor 310, or may comprise machine-readableinstructions and utilized hardware of an application specific integratedcircuit.

In some embodiments, the motion sensor 352 may comprise one or moreforce sensitive switches, e.g., a piezo element configured to generatean electric signal representative of an amount of acceleration that ahealth-monitor patch experiences. In other embodiments, the motionsensor 352 may additionally or alternatively comprise one or morecontact switches that close a circuit, or open a circuit, when thehealth-monitor patch is subjected to an acceleration, e.g., a“ball-in-tube” switch. Wake-up may, for example, be initiated when afrequency of switch closures exceeds a pre-selected value. In otherembodiments, the sensor 352 may additionally or alternatively compriseone or more force-sensitive contact switches that close only when ahealth-monitor patch undergoes acceleration in excess of a pre-selectedvalue.

According to some embodiments, a health-monitor patch may include anelectro-optic display (e.g., a liquid-crystal display, an OLED display,one or more LEDs) and be configured to recognize one or more tappingsequences and/or motion gestures (e.g., moving the device in a figure-8pattern, a circle pattern, a back-and-forth linear pattern). Responsiveto recognition of a tapping sequence or gesture, a health-monitor patchmay activate the display to communicate information or a summary ofinformation stored on the patch. A tapping sequence or gesture maycorrespond to a particular information query, to which thehealth-monitor patch may respond by indicating with the display relevantinformation. According to one embodiment, the health-monitor patch maybe tapped in a particular manner, and in response activate a number ofLEDs to indicate that a user has reached an approximate percentage of anactivity goal (e.g., illuminating 8 of 10 LEDs to signal approximately80%). An activity goal may be preprogrammed into the health-monitorpatch by a user of physician using another electronic device such as acomputer or smart phone that can communicate wirelessly with thehealth-monitor patch. Information about progress toward one or moreactivity goals can be communicated by the device (e.g., walked 30% of agoal of 3 miles, ran 60% of a goal of 8 miles, swam 90% of a goal of 60laps, achieved 70% of creditable health-beneficial activity for the day,achieved 50% of a recommended number of health credits for a week, etc.)A display may also be used to communicate other information responsiveto particular tapping sequences or gestures, e.g., battery life, pacecomparison (ahead of, or behind, best pace for an activity), heart rate,calories burned, etc.

Data may also be communicated to and from a health-monitor patch using awireless communication protocol (e.g., Bluetooth, BluetoothLE, BluetoothSmart, a modified Bluetooth protocol, Wi-Fi, etc.). For example, awireless transceiver and antenna may be included with a health-monitorpatch and used to transmit and receive data to and from a remote devicesuch as a smart phone, smart watch, computer, tablet, etc.

According to some embodiments, a health-monitor patch may include atleast one light source 286 and at least one photodetector 287. The atleast one light source and photodetector may be used, for example, forsensing one or more physiological parameters of a subject, e.g., bloodoxygenation level, plethysmography waveforms, blood glucose level, bloodflow rate, etc. In some embodiments, the light source 286 may comprise ahigh-brightness infrared (IR) photodiode and a shorter wavelengthphotodiode. In recent years, progress in indium-gallium-nitride LEDtechnology has yielded devices with both lowered junction voltage andincreased radiated intensity. Using InGaN technology, and applying powermanagement techniques described in U.S. patent application Ser. No.13/840,098, to which this application claims priority, may provide ahealth-monitor patch capable of measuring heart rate and/or otherphysiological parameters that can run for a week or more on one or morecoin-cell silver-oxide batteries. The photodetector 287 may be anysuitable photodetector (e.g., one or more silicon photodiodes that mayinclude a wavelength filter), and may be mounted to detect light fromthe light source that is scattered or reflected from the subject.

FIG. 4 depicts an exploded view of a disposable health-monitor patch400, according to some embodiments. A flexible strip assembly of adisposable health-monitor patch may include a first PCB assembly 405, abattery 305, and a plurality of flexible materials. At least some of theflexible materials or layers may comprise a sheet formed from solidmaterial (e.g., a polymer film, cloth, polymer or cloth mesh, etc.) thatprovides tensile strength and shape retention for a health-monitorpatch. For example, one or more layers may comprise flexible adhesivetape or films. Some layers may be deposited as a liquid or gel,according to some embodiments. In some cases, the PCB assembly maycomprise a flexible PCB.

According to some embodiments, a battery strap 445 may provide aconnection between a first terminal of the battery 305 (e.g., thepositive terminal) and a battery conductor 480. The battery strap andconductor may be formed from a conductive metal and/or conductivepolymer (e.g., a conductive carbon vinyl film which may or may not becoated with a film comprising silver. The battery 305 may be a coin-celltype battery having a diameter between about 10 mm and about 20 mm, andmay be located adjacent to an insulating ring 410 that helps toelectrically isolate the two terminals of the battery. A second terminalof the battery may electrically connect to a noise/ground conductor 470.The noise/ground conductor may also connect to a noise electrode 270 onthe disposable health-monitor patch 400. According to someimplementations, the noise/ground conductor 470 may further connect to aground contact (not shown) located on the PCB assembly 405.

There may be additional conductors that connect to the monitorelectrodes of a disposable health-monitor patch. For example a firstmonitor conductor 460 a may provide electrical connection between afirst monitor electrode 260 a and a first signal input pad (not shown)of the PCB assembly 405. A second monitor conductor 460 b may provideelectrical connection between a second monitor electrode 260 b and asecond signal input pad (not shown) on the PCB assembly 405. The firstmonitor conductor 460 a, the second monitor conductor 460 b, the batteryconductor 480, and the noise/ground conductor 470 may be formed from aconductive polymer which may or may not be adhesive. In some embodimentsthese conductors may be formed from a carbon vinyl polymer or coatedvinyl polymer. An example of a coated vinyl polymer that may be used fora flexible conductor is model 6355, available from Coveris AdvancedCoatings of Matthews, N.C. In some implementations, one or more of theconductors may be formed from a flexible PCB. In some embodiments, thefirst monitor conductor 460 a, the second monitor conductor 460 b, thebattery conductor 480, and the noise/ground conductor 470 may be cut orpunched from a film of the conductive polymer.

Below the conductors may be a conductor adhesion layer 425 to which theconductors may be adhered. The conductor adhesion layer 425 may retainthe conductors in place as the disposable health-monitor patch flexes ona subject. In some embodiments, the conductor adhesion layer 425 may bea silicone adhesive layer that is electrically insulating. According tosome implementations, the conductor adhesion layer 425 may have adhesivesurfaces on opposing sides (e.g., double-sided adhesive). An example ofa conductor adhesion layer 425 is model 96022 silicone adhesive,available from 3M Corporation of St. Paul, Minn. According to someembodiments, the conductor adhesion layer 425 may be cut and/or punchedfrom a film of the adhesive material.

According to some embodiments, there may be conductive adhesive elements415 located above the battery and signal conductors. The conductiveadhesive elements may have adhesion surfaces on opposing sides. Theseelements may be formed in a similar shape to the conductors 460 a, 460b, 470, 480 from a flexible conductive adhesive film. The conductiveadhesive elements 415 can provide electrical connection between theunderlying conductors and contact pads on the PCB assembly and terminalson the battery 305. The conductive adhesive elements 415 can also adherethe underlying conductors, PCB assembly, and battery together into aflexible assembly. A conductive adhesive element may be formed fromadhesive film, model 9719 (an isotopically conductive pressure sensitivetape), available from 3M Corporation of St. Paul, Minn., according tosome embodiments. The conductive adhesive elements 415 may be cut orpunched from a film of conducting adhesive.

In some cases, an insulating layer 430 may be located below theconductor adhesion layer 425. The insulating layer 430 may provide somestiffness to the lower layers and help retain the monitor electrodes 260a, 260 b and the noise electrode 270. In some cases, insulating layer430 may comprise a foam material having an adhesive surface on one side,an example of which is model 1774W, available from 3M Corporation of St.Paul, Minn. The adhesive surface may be facing the conductors 460 a, 460b, 470, 480, for example. The insulating layer 430 may be cut or punchedfrom a film of the material.

In some embodiments, there may be a surface adhesion layer 435 thatadheres to the insulating layer 430. An example of a surface adhesionlayer 430 is model 96022 silicone adhesive, available from 3MCorporation of St. Paul, Minn., though other suitable adhesion layersmay be used. According to some embodiments, the surface adhesion layer430 may be cut and/or punched from a film of the adhesive material.

According to some aspects, a skin adhesion layer 490 may be attached tothe insulator layer 430. The skin adhesion layer 490 may include anadhesion surface 252 that provides a durable adhesion to the skin of thesubject. Any suitable skin adhesive material may be used for the skinadhesion layer 490. According to some embodiments, a suitable acrylicskin adhesive available from Avery Dennison of Glendale, Calif. may beused as a skin adhesion layer 490. One example of a skin adhesion layer490 is a Tegaderm adhesive, model 1626W, available from 3M Corporationof St. Paul, Minn., though other biocompatible adhesion layers may beused. In some implementations, a hydrocolloid adhesive, model H011,available from Adhesive R&D of Eau Claire, Wis. may be used for the skinadhesion layer. A skin adhesion layer 490 may include a release liner(not shown) over the adhesion surface, that is removed prior to adheringthe disposable health-monitor patch 400 to a subject. An example releaseliner is model 1361 liner, available from 3M Corporation of St. Paul,Minn. In some implementations, a skin adhesion layer 490 may be cutand/or punched from a film of the material.

Upper layers of a disposable health-monitor patch 400 may include aninsulating adhesive layer 450 and an electrostatic discharge (ESD)shield 455 that extend over the battery 305, the PCB assembly 405, and amajority of the conductive adhesive elements 415. In some cases, theremay be a hole or notch in the insulating adhesive layer 450 that allowsthe noise/ground conductor 470 to electrically connect to the ESD shield455, which may be located adjacent to the insulating adhesion layer 450.The insulating adhesive layer 450 may have adhesive surfaces on opposingsides, or may have a single adhesive surface. An example insulatingadhesive layer is adhesive model 9474LE, available from 3M Corporationof St. Paul, Minn., though other insulating adhesive layers may be usedin other embodiments. An example double-sided, insulating, adhesivelayer having different adhesion properties on opposing sides (e.g., adifferential adhesive) include adhesive model 9425, available from 3MCorporation of St. Paul, Minn. The insulating adhesive layer 450 may becut and/or punched from a film of the adhesive material.

In some embodiments, an ESD shield 455 may extend over at least aportion of the first monitor conductor 460 a and at least a portion ofthe second monitor conductor 460 b. The ESD shield may furtherelectrically connect to the noise electrode 270 via the noise/groundconductor 470. The ESD shield may be insulated from the first monitorconductor and the second monitor conductor, but be located in closeproximity (e.g., less than about 2 mm) to the two conductors (e.g.,arranged as parallel plates in some locations). The ESD shield may beformed from a conductive polymer, according to some embodiments. Anexample conductive polymer is coated carbon vinyl film, model 6355,available from Coveris Advanced Coatings of Matthews, N.C., thoughuncoated conductive films may be used.

According to some embodiments electrical noise transmitted across theskin of the subject may be picked up by the noise electrode 270 andconducted to the ESD shield 455. This noise may then couple into thefirst monitor conductor 460 a and the second monitor conductor 460 bfrom the ESD shield due to the close proximity of the ESD overlying thefirst monitor conductor 460 a and second monitor conductor 460 b. Insome embodiments, the amount of signal coupled to each monitor electrodemay have similar amplitudes (e.g., within about ±15%). A differentialamplifier may be arranged at a signal input of the PCB assembly 405 toamplify signals received from the first monitor electrode 260 a andsecond monitor electrode 260 b. Since the noise is coupled into the twoconductors and inputs of the differential amplifier, it may be reducedor cancelled via common-mode rejection.

According to some embodiments, there may be an adhesive cover layer 402attached over the ESD shield 455 that covers the disposablehealth-monitor patch 400. The adhesive cover layer 402 may comprisecloth, foam, a flexible polymer (such as silicone), or any othersuitably flexible material. In some embodiments, a cover layer 402 maycomprise a second layer of the same material used for the insulatinglayer 430. The cover layer may be cut or punched from a film of thematerial. In some instances, the cover layer 402 and insulating layer430 may comprise sealed foam or a suitable water resistant or waterproofmaterial to reduce ingress of water to the PCB assembly 405 and battery305.

Some components of a disposable health-monitor patch are depicted in theelevation view of FIG. 5, according to some embodiments. The depictionshows a PCB assembly 405 that connects to the first monitor electrode260 a via a conductive adhesive element (depicted as a gray line) andthe first monitor conductor 460 a. The PCB assembly 405 alsoelectrically connects to the second monitor electrode 260 b via aconductive adhesive element (gray line) and the second monitor conductor460 b. The battery 305 and its conductors are not depicted in FIG. 5 tosimplify the drawing.

In some implementations, the ESD shield 455 is disposed over the PCBassembly 405, the first monitor conductor 460 a, and the second monitorconductor 460 b. There may be an insulating adhesion layer 450 betweenthe ESD shield 455 and the conductive adhesive elements. The insulatinglayer may include an opening 452 (also depicted in FIG. 4) between theESD shield 455 and the conductive adhesive element 415 that is locatedover the noise/ground conductor 470. The opening allows an electricalconnection to be made between the ESD shield 455 and the noise electrode270 when the layers of the health-monitor patch are all pressedtogether.

Further details of a repeated-use health-monitor patch 100 are depictedin the elevation view of FIG. 6, for some implementations. Theillustration shows an arrangement of components for the deviceillustrated in FIGS. 1A-1C, according to some embodiments. Within theflexible strip assembly 105, there may be a PCB assembly 405 and abattery 305. The flexible strip assembly 105 may further includeconductive elements (not all shown) that provide electrical connectionbetween terminals of the battery and power/ground pads on the PCBassembly and one or more noise electrodes or sensing components, andbetween signal inputs on the PCB assembly and monitor electrodes 160 a,160 b. The noise electrode and monitor electrodes may be located on thereplaceable electrode strip 150, which is shown separated from theflexible strip assembly.

According to some embodiments, there may be electrical connectionsbetween various components of a health-monitor patch. For example, apatterned flexible PCB may be used to form electrical connectionsbetween a monitor electrode and a PCB assembly 405. The inventors haverecognized and appreciated that linkages between a flexible conductor(e.g., a flexible PCB) and a more rigid electrical component (e.g., aPCB assembly 405) can be improved by adding strain-relief material at aninterface of the flexible conductor. For example, silicone, polyimide,or a thermal set adhesive may be added to reinforce and provide strainrelief at a junction between a flexible conductor and a more rigidelectrical component.

In some embodiments, the flexible strip assembly 105 may be formed inpart from flexible silicone. For example, the silicone may be applied ingel or liquid form into a mold to cover electronic components of ahealth-monitor patch. The resulting silicone casing 605 may extendentirely around the battery 305, the PCB assembly 405, and theassociated conductors. The silicone may then be cured, so that theassembly 105 can be highly flexible and completely waterproof. Awaterproof enclosure may allow the health-monitor patch to be worn on asubject and immersed in water. Further, adhesives used for thereplaceable electrode strip 150 form watertight seals with the siliconecasing 605 and skin of a subject. The inventors have recognized andappreciated that conventional activity monitors that sense heart rate donot perform well or at all when immersed in water. The siliconeenclosure may allow the health-monitor patch to monitor activity andphysiological parameters of a swimmer, surfer, windsurfer, kiteboarder,etc.

Since, in some implementations, the on-board battery may be fullyencased in silicone, wireless charging may be used to recharge theon-board battery. In some embodiments, a coil and rectifying circuit maybe included in a health-monitor patch so that electromagnetic energy maybe wirelessly coupled to the coil from a wireless charger. Energycoupled to the coil may be rectified and used to charge the battery.

Although silicone provides a flexible and robust environmental seal, itis an electrical insulator. The inventors have conceived of locallymodifying the silicone so that electrical connection through thesilicone to the monitor and noise electrodes of the replaceableelectrode strip 150 can be achieved. According to some embodiments, theelectrical connections do not require metal wires or inflexible metalpads at the surface of the silicone casing 605.

According to some embodiments, the silicone casing may be infused withcarbon or other conductive materials at surface locations thatcorrespond to locations of the monitor electrodes 160 a, 160 b and noiseelectrode(s) 170 on the replaceable electrode strip 150. For example,the flexible strip assembly 105 may include a first infused monitorelectrode 660 a and a second infused monitor electrode 660 b. Theflexible strip assembly may further include one or more infused noiseelectrodes 670.

The carbon-infused electrodes may be formed, according to someembodiments, using a double-injection process. For example, a firstinjection of uncured, carbon-infused silicone may be used to form theinfused electrodes 660 a, 660 b, 670 at the correct locations.Conductive carbon powder may be premixed into the silicon to make thesilicone conductive. A second silicone injection may then be used toform the remaining casing 605 of the flexible strip assembly. The secondsilicone injection may comprise insulating silicone. The first injectionmay be uncured, partially cured, or fully cured prior to the secondinjection.

Internal conductors 672 (e.g., conductors on a flexible PCB orconductors made from a flexible conductive film) may electricallyconnect to a corresponding infused electrode. (Not all conductors areshown in FIG. 6.) For example, the carbon-infused silicone may beinjected around an exposed end of a conductor. The conductor may thenprovide an electrical connection to a signal input on the PCB assembly405 or to the ESD shield 455. The infused electrode may provideelectrical conduction between a conductor and another conductive elementon the replaceable electrode strip.

An embodiment showing further details of a replaceable electrode strip150 is illustrated in FIG. 7A. The components are shown in an explodedelevation view in FIG. 7A and depicted in an assembled elevation view inFIG. 7B. In some implementations, a replaceable electrode strip maycomprise a first release liner 710 sealing a top adhesive surface of thereplaceable electrode strip and a second release liner 712 covering askin adhesion surface 152 of the replaceable electrode strip. In someimplementations, the first and second release liners may be releaseliner model 1361, available from 3M Corporation of St. Paul, Minn.,though other liners may be used in other embodiments. The first releaseliner may be removed prior to adhering the replaceable electrode strip150 to the bottom (skin-side) surface of the flexible strip assembly105. The second release liner may be removed prior to adhering theflexible strip assembly and replaceable electrode strip to the skin of asubject.

A replaceable electrode strip 150 may further include a patch adhesionlayer 720 that provides adhesion of the replaceable electrode strip tothe flexible strip assembly 105 (e.g., to the silicone casing 605). Thepatch adhesion layer may comprise adhesive surfaces 722, 726 on opposingsides in some cases. In some implementations, the adhesive surfaces maybe formed of a same material. In other embodiments, the adhesivesurfaces may be formed of a different material. Examples of double-sidedadhesives formed of same materials may include adhesive models 96042 or9474LE, available from 3M Corporation of St. Paul, Minn. An exampledouble-sided adhesive having different adhesion properties on opposingsides (e.g., a differential adhesive) include adhesive model 9425,available from 3M Corporation of St. Paul, Minn. The patch adhesionlayer may be configured to adhere to silicone on a first adhesive side722 and an underlying layer of the replaceable electrode strip on asecond adhesive side 726.

In some embodiments, the patch adhesion layer 720 may include vias 725that expose conductive adhesive disks 730 when the first release liner710 is removed. The vias 725 may have a diameter between about 5 mm andabout 20 mm, according to some embodiments. The conductive adhesivedisks 730 may have a diameter approximately 2 mm to approximately 6 mmlarger than the diameter of the vias 725.

In some implementations, the conductive adhesive disks 730 may be formedfrom conductive adhesive model 9713 (an isotropically conductivepressure sensitive tape), available from 3M Corporation of St. Paul,Minn., though other conductive adhesives may be used in some cases. Theconductive adhesive disks 730 may adhere to infused silicone electrodes660 a, 660 b, 670 on one side and to conductive disks 740 on an opposingside and provide electrical connections between the infused electrodesand conductive disks. The conductive adhesive disks 730 may also adhereto the patch adhesion layer 720 and retain the conductive disks 740 in adesired location (e.g., aligned to electrodes 160 a, 160 b, 170). Theflexible conductive disks 740 may be formed from a conductive polymer,such as a carbon vinyl film model 6355, available from Coveris AdvancedCoatings of Matthews, N.C., though other conductive films may be used insome cases. A diameter of the conductive disks 740 may be betweenapproximately 1 mm and approximately 6 mm smaller than the diameter ofthe conductive adhesive disks 730, according to some embodiments. Insome embodiments, a diameter of the conductive disks 740 may be equal toor larger than the diameter of the conductive adhesive disks 730.

A replaceable electrode strip 150 may further include a skin adhesionlayer 750. The skin adhesion layer 750 may be electrically insulatingand include vias 745 that expose the conductive disks 740 to underlyingelectrodes 160 a, 160 b, 170. The diameter of the vias 745 may be lessthan or greater than the diameter of the conductive disks 740. Anexample of a skin adhesion layer 750 is a Tegaderm adhesive, model1626W, available from 3M Corporation of St. Paul, Minn., though otherbiocompatible adhesive layers may be used. In some implementations, ahydrocolloid adhesive, model H011, available from Adhesive R&D of EauClaire, Wis. may be used for the skin adhesion layer 750.

The vias 745 of the skin adhesion layer 750 may accommodate the monitorelectrodes 160 a, 160 b and the noise electrode(s) 170, according tosome embodiments. These electrodes may be formed from a hydrogel, e.g.,X863 Hydrogel available from Adhesive R&D of Eau Claire, Wis., thoughany other suitable hydrogel may be used. The diameter of the electrodesmay be between approximately 5 mm and approximately 20 mm, in somecases. In some embodiments, the diameter of the electrodes may bebetween approximately 8 mm and approximately 16 mm.

In some implementations, one or more of the electrodes 160 a, 160 b, 170may be surrounded laterally by an adhesive ring 765. The adhesive ringmay be insulating, according to some embodiments. The adhesive rings maybe formed from adhesive model 1774W, available from 3M Corporation ofSt. Paul, Minn., though other adhesives may be used to form adhesiverings 765.

FIG. 7B shows components of a replaceable electrode assembly 150 pressedtogether to bond the different layers and components into an assembly.In some embodiments, the hydrogel may be injected after pressing thelayers and other components together and prior to applying the secondrelease liner 712. According to some embodiments, the flexible layersand components of the replaceable electrode assembly 150 (apart from thehydrogel electrodes) may be cut and/or punched to a suitable shape whenmanufacturing the assembly. Referring again to FIG. 4, flexible layersand components of a disposable health-monitor patch 400 (apart from thehydrogel electrodes, PCB assembly, and battery) may be cut and/orpunched to a suitable shape when manufacturing the assembly. Theinventors have recognized and appreciated that multiple layers andcomponents of a replaceable electrode assembly 150 and a disposablehealth-monitor patch 400 may be formed and assembled using reel-to-reelor “converter” manufacturing processes. This can greatly reducemanufacturing costs for producing a health-monitor patch or replaceableelectrode strip.

In some embodiments, two or more “levels” of a disposable health-monitorpatch or replaceable electrode strip may be assembled using a converterprocess to form a first composite. Separately, two or more additionallevels may be assembled using a converter process to form a secondcomposite. Then, the two composites may be assemble using a converterprocess.

For example and referring to FIG. 7A, a first composite may be assembledin a converter process by unrolling a release liner 710 from a firstroll (level 1), punching vias 725 in a sheet from a second rollcomprising patch adhesion layer 720 (level 2), and perforatingconductive adhesive disks 730 from a third roll comprising a conductiveadhesive (level 3). Perforating a layer may allow the disks 730 (orother component) to be weakly retained in the sheet of material, andsubsequently broken or torn free from the sheet when bonding to anotherlayer.

The three levels may then be pressed together to form a first composite,and excess material from the conductive adhesive roll may be removed.Similar processing may be used to assemble the conductive disks 740(level 4), skin adhesion layer 750 (level 5), and adhesive rings 765(level 6) to form a second composite. The first and second compositesmay then be aligned and pressed together in a converter process.Subsequently, the hydrogel electrodes 160 a, 160 b, 170 may be injectedand the second release liner 712 applied. Finally, the replaceableelectrode assembly 150 may be punched from the assembled composites andpackaged. Other suitable manufacturing processes may be used in otherembodiments.

When placed in operation, a health-monitor patch (repeated-use ordisposable) may detect full PQRST waveform profiles or portions of PQRSTwaveform profiles of a subject continuously or intermittently, accordingto some implementations. An illustration of a PQRST waveform profile isdepicted in FIG. 8. The detected waveforms may be processed (e.g., byprocessor 310, digital signal processing circuitry, or any suitablesignal processing circuitry) to determine one or more physiologicalparameters. Physiological parameters that may be determined by ahealth-monitor patch from cardiac waveforms may include heart rate,inter-beat interval (IBI), heart rate variability (HRV), arrhythmia, andrespiration rate, for example.

According to some embodiments, electronic filtering may be used topre-process a cardiac waveform. For example, filtering may be used toreduce noise, pass or block certain frequency components, or emphasizeaspects of a PQRST waveform so that a particular parameter (e.g., heartrate, HRV, arrhythmia, etc.) may be determined by a processor 310 moreaccurately, for example. A cardiac waveform 910 recorded by ahealth-monitor patch of an example embodiment is plotted in FIG. 9. Thesignal has been pre-processed by on-board circuitry to emphasize aspectsof the R wave, so that heart rate may be determined more accurately.According to some embodiments, different signal processing schemes maybe employed to emphasize selected aspects of a cardiac waveform, so thata recorded or analyzed waveform may be different from those shown inFIG. 8 and FIG. 9.

According to some implementations, power conservation for ahealth-monitor patch may, at least in part, be based on cardiac datareceived from a cardiac sensor and/or motion data received from anaccelerometer. Power conservation methods based on cardiac data may runin parallel with or in combination with power conservation methods basedon motion data. In some cases, a power conservation mode of operationmay be determined in part based upon a health condition of the subject.For example, recovering patients or individuals presenting a healthimpairment may need more continuous and/or full monitoring of cardiacwaveform and/or activity/motion data, whereas less monitoring of cardiacwaveforms and activity data may be needed for fit individuals. Selectionor setting of power-conservation mode options may be made via wirelesscommunication with the health-monitor patch or via a tapping sequence orgesture recognizable by the health-monitor patch.

To extend battery life, a health-monitor patch may cycle through one ormore operational modes that consume different amounts of power dependingon the state of the subject. As just one illustrative embodiment ofpower conservation, motion data may be analyzed by a system processor todetermine that a subject is in an inactive state (e.g., sitting, lying,riding in a vehicle, etc.). A health-monitor patch may then determinethat at least power to an accelerometer may be reduced. In someembodiments, circuitry and processing algorithms associated with theaccelerometer may enter a sleep or reduced-power mode. In someembodiments, a cardiac sensor of the same health-monitor patch may alsoenter a sleep mode in which a full cardiac waveform is not recorded.Instead, portions of a cardiac waveform (e.g., only R-wave portions), ornone of a cardiac waveform, may be recorded and/or processed. In someimplementations, portions of the cardiac waveform may be recorded andprocessed intermittently (e.g., skipping one or more beats betweenrecordings). In other embodiments, a cardiac sensor may continue tosense a full cardiac waveform while an inactive state of the subject hasbeen detected (e.g., to monitor a cardiac parameter for a patient).

In some embodiments, a full-power continuous detection mode may beautomatically activated when the health-monitor patch determines thatthe subject is active based on data from the accelerometer. In someimplementations, a power management circuit of a health-monitor patchmay place a cardiac sensor in a power-conserving state when a subject isactive. For example, a health-monitor patch may determine that asubject's heart rate is stable during an activity, and may then placethe cardiac sensor in a power-conserving state in which portions of thecardiac cycle are monitored continuously or intermittently.

Additional examples of power-conserving modes include, but are notlimited to, a beat-detect mode, a QRS-detect mode, and a full-wave mode.In a beat-detect mode, a heart monitor may sleep for a period of timebetween each heartbeat of a subject and awake in time only to determinea point or timing in the cardiac waveform that is sufficient to indicatean inter-beat interval (IBI). For example, the cardiac sensor may awakein time to detect a portion of the cardiac waveform corresponding to anR wave. In some implementations, the cardiac signal may be fed to acomparator or processor configured to detect a threshold crossing orchange in slope (e.g., location of a peak) of the R wave. A comparatormay require less power to operate than circuitry needed to capture andanalyze a portion of the cardiac waveform.

In a QRS-detect mode, a cardiac sensor may sleep for a period of timebetween each heartbeat of a subject and “awake” in time to capture a QRSwaveform for subsequent analysis. The QRS waveform may, for example, beanalyzed by a processor for arrhythmia, heart rate variability, and/orrespiration rate, according to some implementations. In someembodiments, respiration rate may be determined from an envelope of theR-wave over multiple cardiac cycles.

In a full-wave mode of operation, a heart monitor may operatecontinuously to capture a full cardiac waveform for multiple beats. Afull-wave mode of operation may be executed periodically to ascertainthe timing of P or R waves, for example, and determine an interval ofsleep for a cardiac monitor between heartbeats. In some implementations,a full-wave mode of operation may be executed when a subject becomesactive, or may be executed when a subject's activity is found to bemoderate and/or vigorous. In some implementations, a user may commandcontinuous monitoring of a cardiac waveform and/or other physiologicalparameters irrespective of the user's activity by communicatingwirelessly with, or tapping a sequence on, the health-monitor patch thatcan be detected by the motion sensor, processed, and recognized by thehealth-monitor patch's processor as a command to record full-wave,continuous data.

Additional embodiments of power-conserving modes and processing cardiacsignals are described in U.S. Patent Application Pub. No. 2015-0119728,incorporated by reference above.

All literature and similar material cited in this application,including, but not limited to, patents, patent applications, articles,books, treatises, and web pages, regardless of the format of suchliterature and similar materials, are expressly incorporated byreference in their entirety. In the event that one or more of theincorporated literature and similar materials differs from orcontradicts this application, including but not limited to definedterms, term usage, described techniques, or the like, this applicationcontrols.

The section headings used herein are for organizational purposes onlyand are not to be construed as limiting the subject matter described inany way.

While various inventive embodiments have been described and illustratedherein, those of ordinary skill in the art will readily envision avariety of other means and/or structures for performing the functionand/or obtaining the results and/or one or more of the advantagesdescribed herein, and each of such variations and/or modifications isdeemed to be within the scope of the inventive embodiments describedherein. More generally, those skilled in the art will readily appreciatethat all parameters, dimensions, materials, and configurations describedherein are meant to be exemplary and that the actual parameters,dimensions, materials, and/or configurations will depend upon thespecific application or applications for which the inventive teachingsis/are used. Those skilled in the art will recognize, or be able toascertain using no more than routine experimentation, many equivalentsto the specific inventive embodiments described herein. It is,therefore, to be understood that the foregoing embodiments are presentedby way of example only and that, within the scope of the appended claimsand equivalents thereto, inventive embodiments may be practicedotherwise than as specifically described and claimed. Inventiveembodiments of the present disclosure are directed to each individualfeature, system, article, material, and/or method described herein. Inaddition, any combination of two or more such features, systems,articles, materials, and/or methods, if such features, systems,articles, materials, and/or methods are not mutually inconsistent, isincluded within the inventive scope of the present disclosure.

The above-described embodiments of the invention can be implemented inany of numerous ways. For example, some embodiments may be implementedusing hardware, software or a combination thereof. When any aspect of anembodiment is implemented at least in part in software, the softwarecode can be executed on any suitable processor or collection ofprocessors, whether provided in a single computer or distributed amongmultiple computers.

In this respect, various aspects of the invention, e.g., processingsignals from monitor and noise electrodes, may be embodied at least inpart as a computer readable storage medium (or multiple computerreadable storage media) (e.g., a computer memory, one or more floppydiscs, compact discs, optical discs, magnetic tapes, flash memories,circuit configurations in Field Programmable Gate Arrays or othersemiconductor devices, or other tangible computer storage medium ornon-transitory medium) encoded with one or more programs that, whenexecuted on one or more computers or other processors, perform methodsthat implement the various embodiments of the technology discussedabove. The computer readable medium or media can be transportable, suchthat the program or programs stored thereon can be loaded onto one ormore different computers or other processors to implement variousaspects of the present technology as discussed above.

Various aspects of a health-monitor patch described above may beimplemented in hardware, software, firmware, or a combination thereof.For example, any of the operational aspects of a health-monitor patchwhich involve processing data, handling data, and/or communications maybe implemented as stored machine-readable instructions that areexecutable by a processor and embodied on at least one tangible,computer-readable storage device. The instructions may be executed orplaced in operation on a digital processor of a health-monitor patch. Insome implementations, instructions may be placed in operation on acentral hub or server that operates in combination with operation of ahealth-monitor patch.

The terms “program” or “software” are used herein in a generic sense torefer to any type of computer code or set of machine-executableinstructions that can be employed to program a computer or otherprocessor to implement various aspects of the present technology asdiscussed above. Additionally, it should be appreciated that accordingto one aspect of this embodiment, one or more computer programs thatwhen executed perform methods of the present technology need not resideon a single processor, but may be distributed in a modular fashionamongst a number of different processors to implement various aspects ofthe present technology.

Computer-executable instructions may be in many forms, such as programmodules, executed by one or more computers or other devices. Generally,program modules include routines, programs, objects, components, datastructures, etc. that perform particular tasks or implement particularabstract data types. Typically the functionality of the program modulesmay be combined or distributed as desired in various embodiments.

Also, the technology described herein may be embodied as a method, ofwhich at least one example has been provided. The acts performed as partof the method may be ordered in any suitable way. Accordingly,embodiments may be constructed in which acts are performed in an orderdifferent than illustrated, which may include performing some actssimultaneously, even though shown as sequential acts in illustrativeembodiments.

All definitions, as defined and used herein, should be understood tocontrol over dictionary definitions, definitions in documentsincorporated by reference, and/or ordinary meanings of the definedterms.

The indefinite articles “a” and “an,” as used herein in thespecification and in the claims, unless clearly indicated to thecontrary, may be used to mean “at least one.”

The phrase “and/or,” as used herein in the specification and in theclaims, should be understood to mean “either or both” of the elements soconjoined, i.e., elements that are conjunctively present in some casesand disjunctively present in other cases. Multiple elements listed with“and/or” should be construed in the same fashion, i.e., “one or more” ofthe elements so conjoined. Other elements may optionally be presentother than the elements specifically identified by the “and/or” clause,whether related or unrelated to those elements specifically identified.Thus, as a non-limiting example, a reference to “A and/or B”, when usedin conjunction with open-ended language such as “comprising” can refer,in one embodiment, to A only (optionally including elements other thanB); in another embodiment, to B only (optionally including elementsother than A); in yet another embodiment, to both A and B (optionallyincluding other elements); etc.

As used herein in the specification and in the claims, “or” should beunderstood to have the same meaning as “and/or” as defined above. Forexample, when separating items in a list, “or” or “and/or” shall beinterpreted as being inclusive, i.e., the inclusion of at least one, butalso including more than one, of a number or list of elements, and,optionally, additional unlisted items. Only terms clearly indicated tothe contrary, such as “only one of” or “exactly one of,” or, when usedin the claims, “consisting of,” will refer to the inclusion of exactlyone element of a number or list of elements. In general, the term “or”as used herein shall only be interpreted as indicating exclusivealternatives (i.e. “one or the other but not both”) when preceded byterms of exclusivity, such as “either,” “one of” “only one of” or“exactly one of” “Consisting essentially of,” when used in the claims,shall have its ordinary meaning as used in the field of patent law.

As used herein in the specification and in the claims, the phrase “atleast one,” in reference to a list of one or more elements, should beunderstood to mean at least one element selected from any one or more ofthe elements in the list of elements, but not necessarily including atleast one of each and every element specifically listed within the listof elements and not excluding any combinations of elements in the listof elements. This definition also allows that elements may optionally bepresent other than the elements specifically identified within the listof elements to which the phrase “at least one” refers, whether relatedor unrelated to those elements specifically identified. Thus, as anon-limiting example, “at least one of A and B” (or, equivalently, “atleast one of A or B,” or, equivalently “at least one of A and/or B”) canrefer, in one embodiment, to at least one, optionally including morethan one, A, with no B present (and optionally including elements otherthan B); in another embodiment, to at least one, optionally includingmore than one, B, with no A present (and optionally including elementsother than A); in yet another embodiment, to at least one, optionallyincluding more than one, A, and at least one, optionally including morethan one, B (and optionally including other elements); etc.

The claims should not be read as limited to the described order orelements unless stated to that effect. It should be understood thatvarious changes in form and detail may be made by one of ordinary skillin the art without departing from the spirit and scope of the appendedclaims. All embodiments that come within the spirit and scope of thefollowing claims and equivalents thereto are claimed.

What is claimed is:
 1. A system that is configured to be supported by asubject, the system comprising: a processor; an accelerometer; at leastone light source configured to interrogate a region of the subject; andat least one photodetector configured to receive radiation from the atleast one light source which is reflected from or transmitted throughthe region of the subject; wherein the processor is configured to:determine, based at least in part on data received from theaccelerometer at a first time, that a first physiological parameter ofthe subject is to be determined, in response to determining that thefirst physiological parameter is to be determined, cause the at leastone light source to operate and process signals from the at least onephotodetector to determine the first physiological parameter, determine,based at least in part on data received from the accelerometer at asecond time, that a second physiological parameter of the subject, whichis different than the first physiological parameter, is to bedetermined, and in response to determining that the second physiologicalparameter is to be determined, cause the at least one light source tooperate and process signals from the at least one photodetector todetermine the second physiological parameter.
 2. The system of claim 1,wherein the processor is further configured to: cause the at least onelight source to operate in a first manner to determine the firstphysiological parameter; and cause the at least one light source tooperate in a second manner, which is different than the first manner, todetermine the second physiological parameter.
 3. The system of claim 1,wherein the first physiological parameter comprises a blood oxygenationlevel of the subject.
 4. The system of claim 3, wherein the secondphysiological parameter comprises a heart rate of the subject.
 5. Thesystem of claim 3, wherein the second physiological parameter comprisesa blood glucose level of the subject.
 6. The system of claim 3, whereinthe second physiological parameter comprises at least one feature of aplethysmography waveform.
 7. The system of claim 2, wherein the firstphysiological parameter comprises a heart rate of the subject.
 8. Thesystem of claim 7, wherein the second physiological parameter comprisesa blood glucose level of the subject.
 9. The system of claim 7, whereinthe second physiological parameter comprises at least one feature of aplethysmography waveform.
 10. The system of claim 1, wherein: the firstphysiological parameter comprises a blood glucose level of the subject,and the second physiological parameter comprises at least one feature ofa plethysmography waveform.
 11. A method, comprising: interrogating aregion of a subject with light emitted from at least one light source;receiving, with at least one photodetector, radiation from the at leastone light source which is reflected from or transmitted through theregion of the subject; and using a processor to: determine, based atleast in part on data received from an accelerometer at a first time,that a first physiological parameter of the subject is to be determined,in response to determining that the first physiological parameter is tobe determined, cause the at least one light source to operate andprocess signals from the at least one photodetector to determine thefirst physiological parameter, determine, based at least in part on datareceived from the accelerometer at a second time, that a secondphysiological parameter of the subject, which is different than thefirst physiological parameter, is to be determined, and in response todetermining that the second physiological parameter is to be determined,cause the at least one light source to operate and process signals fromthe at least one photodetector to determine the second physiologicalparameter.
 12. The method of claim 11, wherein: using the processor tocause the at least one light source to operate to determine the firstphysiological parameter further comprises using the processor to causethe at least one light source to operate in a first manner; and usingthe processor to cause the at least one light source to operate todetermine the second physiological parameter further comprises using theprocessor to cause the at least one light source to operate in a secondmanner, which is different than the first manner, to determine thesecond physiological parameter.
 13. The method of claim 11, wherein thefirst physiological parameter comprises a blood oxygenation level of thesubject.
 14. The method of claim 13, wherein the second physiologicalparameter comprises a heart rate of the subject.
 15. The method of claim13, wherein the second physiological parameter comprises a blood glucoselevel of the subject.
 16. The method of claim 13, wherein the secondphysiological parameter comprises at least one feature of aplethysmography waveform.
 17. The method of claim 11, wherein the firstphysiological parameter comprises a heart rate of the subject.
 18. Themethod of claim 17, wherein the second physiological parameter comprisesa blood glucose level of the subject.
 19. The method of claim 17,wherein the second physiological parameter comprises at least onefeature of a plethysmography waveform.
 20. The method of claim 11,wherein: the first physiological parameter comprises a blood glucoselevel of the subject; and the second physiological parameter comprisesat least one feature of a plethysmography waveform.